Portable hand-held and mobile vehicular battery operated communication devices operate over a broader range of applications than ever before. The ability to transition from one network or system to another without the user being aware of the transition is typically referred to as seamless mobility. Scan operation, used in such systems, allows monitoring of multiple communication channels, talkgroups and/or resources. Today, devices such as two-way radios, cell phones and the like, often include high end features such as cameras, text messaging, mailbox features and organizers to name a few. These features need to remain operational as the device is transitioned between various systems.
Radio users desire a level of scan performance which is seamless: no audio holes, no missed messages, and no message latency. Such performance is not realizable with a single receiver design, and even a dual receiver design does not guarantee seamless performance in all cases. Furthermore, the use of multiple receivers and faster scanning along with today's high end features all increase battery power consumption which is particularly problematic for the portable device. Scan operation typically prevents or limits standby or “battery save” types of modes, resulting in greater power utilization. Hence, the use of scan operation can necessitate a larger battery or a shorter runtime, again negatively impacting a portable radio.
Accordingly, it would be beneficial to have battery powered communication devices capable of seamlessly transitioning amongst systems without severe degradation of battery life, without impacting or limiting the use of high end features and without impacting the size or weight of the devices.
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